The disclosure pertains to helicopter rotors and to drivelinks for incorporation within helicopter rotors. Rotor systems may incorporate drivelinks for transferring torque between a drive shaft and driven shafts that rotate about misaligned axes. For example, a multilink joint comprising a plurality of drivelinks may be incorporated in a helicopter rotor assembly in order to reduce and/or normalize kinematic errors introduced during operation of the rotor assembly (e.g., oscillatory strain, lateral wobbling, etc.). Examples of such are found in U.S. Pat. No. 5,186,686 and U.S. Pat. No. 4,729,753, both of which are incorporated herein by reference. Such multilink joint may comprise a wobble plate and a plurality of drivelinks coupling drive link trunnions to the wobble plate.
The drivelinks may comprise elastomeric bearings in order to enable movement of the wobble plate within a predetermined, limited range of motion. However, problems arise when constructing an elastomeric bearing that is resilient enough to reduce and/or normalize kinematic error, and which is also strong enough to carry the operational loads. More particularly, problems arise because as elastomeric material is made stronger, its resiliency decreases. As a result, in previous systems comprising drivelinks as the elastomeric bearings are compressed so as to transfer torque loads, the backside of the bearings experience harmful tension (e.g., one side of the bearing is put in compression and the other side of the bearing is put in tension). The tension can pull apart the elastomeric material or the layers of elastomeric material and metal within the bearings, which degrades bearing performance. Therefore, needed is driveshaft comprising an elastomeric bearing that offers effective kinematic performance without experiencing tension.